As a display device for displaying an image, a vehicular display device having a liquid crystal panel (for example, head up display (HUD)) is known (refer to, for example, PTL 1 and PTL 2). In PTL 1, a heat sink is provided at a light source to reduce an influence exerted by heat from the light source. In PTL 2, light having amplitude other than a predetermined direction in sunlight is blocked by providing a polarizing member to reduce an influence exerted by heat radiated from the sun.